Attributes: Rename 'default' option

[clintoncwolfe]

🎛 Description

Currently, to set the value of an attribute in control code, you say:

attribute('user', default: 'bob')

Likewise, in the metadata file, if you set a value, you use:

attributes:
  user:
    default: bob

In addition, in control code, we have the value= method...

attribute('user').value = 'susan'

This sets up a scenario where it might imply that there is some kind of precedence going on, like the Chef Client's default/normal/override/automatic. That has been a major source of confusion in the chef community, which we'd like to avoid.

Moving forward, we want to be clear that while there may be multiple sources for an attribute's value (--attrs, metadata, inline in code) the precedence is entirely determined by the source, not by some additional precedence level dimension.

🌍 InSpec and Platform Version

v3.2.x

💁 Possible Solutions

Introduce 'value' as the only accepted option. Deprecate 'default' over the next two major versions.

Refs #3748